#include <Adafruit_SSD1306.h>
#include <Wire.h>
#include <Arduino.h>

// Constants for pins
const int buttonIncreasePin = 2;
const int buttonDecreasePin = 15;
const int buttonOKPin = 4;
const int redLEDPinRelay = 12;
const int infraredLEDPinRelay = 13;
const int battery = 5;

// Variables for time
int setMinutes = 0;
bool LEDsOn = false;

// OLED display setup
Adafruit_SSD1306 display(128, 64, &Wire, -1);

void setup() {
  // Initialize buttons
  pinMode(buttonIncreasePin, INPUT_PULLUP);
  pinMode(buttonDecreasePin, INPUT_PULLUP);
  pinMode(buttonOKPin, INPUT_PULLUP);

  // Initialize LEDs

  pinMode(redLEDPinRelay, OUTPUT);
  pinMode(infraredLEDPinRelay, OUTPUT);

 // Battery voltage read percentage
  pinMode(battery,INPUT);
  int voltage = analogRead(battery);

  // Initialize display
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.display();
  delay(2000); // Pause for 2 seconds
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 30);
  display.print("Set Time: ");
  display.display();
}

void loop() {
  // Handle button presses
  if (digitalRead(buttonIncreasePin) == LOW) {
    // Increase minutes
    setMinutes++;
    if (setMinutes > 60) {
      setMinutes = 60;
    }
    updateDisplay();
    delay(50); // Debounce delay
  }

  if (digitalRead(buttonDecreasePin) == LOW) {
    // Decrease minutes
    setMinutes--;
    if (setMinutes < 0) {
      setMinutes = 0;
    }
    updateDisplay();
    delay(50); // Debounce delay
  }

  if (digitalRead(buttonOKPin) == LOW) {
    // User confirmed set time
    // Turn on LEDs
    // Normally closed configuration, HIGH signal
    digitalWrite(redLEDPinRelay, HIGH);
    digitalWrite(infraredLEDPinRelay, HIGH);
    delay(5000);
    LEDsOn = true;
  }

  // Check if LEDs should be on based on the set time
  if (LEDsOn) {
    unsigned long currentMillis = millis();
    unsigned long elapsedMinutes = currentMillis / (1000UL * 60); // Calculate elapsed minutes
    if (elapsedMinutes >= setMinutes) {
      // Turn off LEDs
      // Normally closed configuration, LOW signal
      digitalWrite(redLEDPinRelay, LOW);
      digitalWrite(infraredLEDPinRelay, LOW);
      delay(5000);
      LEDsOn = false;
    }
  }

 // Name
  display.setTextSize(1.2);
  display.setCursor(0,0);
  display.print("acuPressure");
  display.display();

  display.setTextSize(0.5);
  display.setCursor(0,10);
  display.print("points stimulator");
  display.display();

  //voltage display
  int voltage = analogRead(battery);
  display.setTextSize(1);
  display.setCursor(0,50);
  float percent = voltage * 100 / 4096 ; 
  display.print("% battery:");
  display.setTextSize(1);
  display.setCursor(90,50);
  display.print(percent);
  display.display();
}

void updateDisplay() {
  display.clearDisplay();
  display.setCursor(0, 30);
  display.print("Set Time: ");
  if (setMinutes < 10) {
    display.print("0");
  }
  display.print(setMinutes);
  display.print(" minutes");
  display.display();
}